A secret U.S. intelligence program to collect emails that is at the heart of an uproar over government surveillance helped foil an Islamist militant plot to bomb the New York City subway system in 2009, U.S. government sources said on Friday.

In February 2010, Zazi pleaded guilty in federal court in Brooklyn, New York, to charges that included conspiracy to use weapons of mass destruction and providing material support to terrorists.

Miller said authorities traced the sender of the email to a suburb of Denver. At the time of Zazi's arrest, U.S. authorities revealed that he had been tracked from Denver to New York, where, after a brief interlude during which U.S. investigators lost track of him, he was arrested by the FBI.

The sources said Representative Mike Rogers, chairman of the House of Representatives Intelligence Committee, was talking about a plot hatched by Najibullah Zazi, an Afghan-born U.S. resident, when he said on Thursday that such surveillance had helped thwart a significant terrorist plot in recent years.

President Barack Obama's administration is facing controversy after revelations of details of massive programs run by the National Security Agency for collecting information from telephone and Internet companies.

On Friday, CBS News correspondent John Miller, a former U.S. intelligence and FBI official, reported that U.S. authorities had discovered the Zazi plot after running across an email sent to a rarely used al Qaeda address that was associated with a notorious bomb-maker based in Pakistan.

Was the internet surveillance program responsible for the capture of the terrorist? Not so fast:

But British and American legal documents from 2010 and 2011 contradict that claim, which appears to be the latest in a long line of attempts to defend secret programs by making, at best, misleading claims that they were central to stopping terror plots. While the court documents don't exclude the possibility that PRISM was somehow employed in the Zazi case, the documents show that old-fashioned police work, not data mining, was the tool that led counterterrorism agents to arrest Zazi. The public documents confirm doubts raised by the blogger Marcy Wheeler and the AP's Adam Goldman, and call into question a defense of PRISM first floated by House Intelligence Committee Chairman Mike Rogers, who suggested that PRISM had stopped a key terror plot.

Not exactly a ringing defense of the program.

Stopping terrorist attacks is an excuse that has been used by both the Bush and Obama administration to justify these intrusive intel programs. Usually, the claims are impossible to verify - or debunk. In this case, public records would seem to show that the administration official responsible for leaking this info is fudging the truth, at best.

An anonymous US government source claims that internet surveillance helped thwart a plot to bomb the New York city subway system.

But Buzzfeed is reporting that public documents contradict that claim.

A secret U.S. intelligence program to collect emails that is at the heart of an uproar over government surveillance helped foil an Islamist militant plot to bomb the New York City subway system in 2009, U.S. government sources said on Friday.

In February 2010, Zazi pleaded guilty in federal court in Brooklyn, New York, to charges that included conspiracy to use weapons of mass destruction and providing material support to terrorists.

Miller said authorities traced the sender of the email to a suburb of Denver. At the time of Zazi's arrest, U.S. authorities revealed that he had been tracked from Denver to New York, where, after a brief interlude during which U.S. investigators lost track of him, he was arrested by the FBI.

The sources said Representative Mike Rogers, chairman of the House of Representatives Intelligence Committee, was talking about a plot hatched by Najibullah Zazi, an Afghan-born U.S. resident, when he said on Thursday that such surveillance had helped thwart a significant terrorist plot in recent years.

President Barack Obama's administration is facing controversy after revelations of details of massive programs run by the National Security Agency for collecting information from telephone and Internet companies.

On Friday, CBS News correspondent John Miller, a former U.S. intelligence and FBI official, reported that U.S. authorities had discovered the Zazi plot after running across an email sent to a rarely used al Qaeda address that was associated with a notorious bomb-maker based in Pakistan.

Was the internet surveillance program responsible for the capture of the terrorist? Not so fast:

But British and American legal documents from 2010 and 2011 contradict that claim, which appears to be the latest in a long line of attempts to defend secret programs by making, at best, misleading claims that they were central to stopping terror plots. While the court documents don't exclude the possibility that PRISM was somehow employed in the Zazi case, the documents show that old-fashioned police work, not data mining, was the tool that led counterterrorism agents to arrest Zazi. The public documents confirm doubts raised by the blogger Marcy Wheeler and the AP's Adam Goldman, and call into question a defense of PRISM first floated by House Intelligence Committee Chairman Mike Rogers, who suggested that PRISM had stopped a key terror plot.

Not exactly a ringing defense of the program.

Stopping terrorist attacks is an excuse that has been used by both the Bush and Obama administration to justify these intrusive intel programs. Usually, the claims are impossible to verify - or debunk. In this case, public records would seem to show that the administration official responsible for leaking this info is fudging the truth, at best.